Automatic headlamp systems are commonly used within automotive vehicles to automatically control the function of the vehicle's headlamps based upon the operating state of the vehicle, an ambient light level and a traffic environment or scene outside of the vehicle. An automatic headlamp system that also controls the high and low beam state of the headlamps has the added advantage of relieving a driver of the distraction of having to switch between low-beam and high-beam settings allowing the driver to focus on the task of driving the vehicle. In particular, an automatic high-beam control system is designed to automatically dim the headlamps from high-beam to low-beam in the presence of lights from an oncoming or preceding vehicle.
Numerous automatic headlamp control systems described above have been developed and implemented. However, these systems have drawbacks in that a driver may be unable to override a command or activation of the system and the driver must deactivate the automatic headlamp control system in order to input their own desired headlamp state. In other solutions, a driver override mechanism is implemented but it may be a permanent state that requires the driver perform another, separate action to re-enable automatic control of the headlamp system. Both of these known systems detract from the purpose of the automatic headlamp system, which is to avoid distracting the driver. In still another solution, the driver override mechanism is based on a timer value which re-enables the high-beams upon expiration of the tinier. A drawback to this solution is that the timeout value does not take into account subsequent events and therefore, the arbitrary timeout of the override timer may cause the high-beams to be re-enabled or turned off during a driving condition that is not desired by the driver.
There is a need for an override strategy for an automatic high-beam control system which allows the driver to override a command or activation of the system (i.e., turning high-beams on or off), yet re-enables automatic control of the system in an intuitive manner thereby avoiding drawbacks associated with known automatic headlamp systems.